Dicyanamide complexes of copper(II), nickel(II) and cobalt(II) with benzimidazole and its 2-alkyl-derivatives

✍ Scribed by Mária Hvastijová; Jiri Kohout; Marián Okruhlica; Jerzy Mroziński; Lothar Jäger

• Publisher: Springer
• Year: 1993
• Tongue: English
• Weight: 424 KB
• Volume: 18
• Category: Article
• ISSN: 0340-4285
• DOI: 10.1007/bf00191127

✦ Synopsis

Dicyanamide complexes of Co 11, Ni n and Co H of the type M[N(CN)z]zL2, where L = benzimidazole, 2-methyl-or 2-ethylbenzimidazole, have been prepared and studied by spectroscopy and magnetochemistry. The complexes, except for Co[N(CN)2]2 (benzimidazole)2, are six-coordinate, involving bidentate bridging dicyanamide groups. While the Ni" complexes have practically octahedral structures, the Cu n complexes are pseudooctahedral with similar tetragonal distortion. The ligand field strength in these complexes depends mainly on the steric effect of the benzimidazole ligands. The Co II complex of benzimidazole is monomeric tetrahedral, but that of 2-ethylbenzimidazole is tetragonal octahedral. The oridging function of dicyanamide in the six-coordinate complexes is realized either through both cyanide or through amide and cyanide nitrogens. The complex Cu[N(CN)2]2 (2-methylbenzimidazole)2 is a weak antiferromagnet (J=-0.1cm-1), exhibiting under ca. 15 K a long-range antiferromagnetic ordering.